1. Field of the Invention
This invention relates to an improved pneumatically operated thermostat construction and to a method of making such a thermostat construction or the like.
2. Prior Art Statement
It is known to applicant to provide a thermostat construction for producing a pneumatic signal in relation to sensed temperature and having a housing means provided with a pneumatically operated set point adjustment diaphragm operatively interconnected to a temperature sensor and a pneumatically operated feedback diaphragm to control valve means for producing the pneumatic signal in an output chamber of the housing means that is defined in part by the feedback diaphragm.
For example, see the following item:
(1) Copending patent application Ser. No. 864,455, filed Dec. 27, 1977.
The thermostat construction of item (1) above has only two diaphragms and a temperature sensor operatively interconnected together to operate a valve unit of the thermostat construction, one of the diaphragms being a pneumatically operated set point adjustment diaphragm and the other diaphragm being a pneumatically operated feedback diaphragm that defines in part the output chamber of the thermostat construction.